Our house is aprox. 25 yrs old. We have a big problem with mildew in lots of places. For instance, I have books in a bookcase and mildew/mold will form on those books. It also forms on the bottoms of wood furniture. One of my neighbors has this same problem but other neighbors don't. Our house is not in a low spot, it is actually high. Someone suggested a dehumidifier for the house. If the dehumidifier is the answer what kind and how big? Another suggested putting a roof fan in the brick at the end of the house to keep air moving under the house. We've been under the house and there is no standing water or anything like that. Can someone help us with this problem?